A camera has a plane receiving surface and based on this surface a co-ordinate system can be defined in which x, y is in the plane of that surface of the camera and z is an axis along the optical path of the camera. Time-of-Flight imaging systems measure the time difference or phase difference between pulsed light emitted from LED's or lasers, e.g. laser diodes, and the reflected pulses. In 3D Time-of-Flight imaging systems, a crucial functionality is to provide not only z data (z being the measured depth map) of the scene in the field of view of the camera, but also IR illumination and color data of the viewed scene and even to provide an image of the scene itself, e.g. in a 3D form embedding at least some color components and the depth values. To do so, one can use two cameras. Another implementation option is to have two sets of pixels array (two sensors) in one single camera. In either way, such color data is then build by a system with 2 separate sensors and lens systems. On top of the increased bill of materials, this approach requires a careful calibration and intensive calculations to map the pixels color data on the depth data and vice-versa. The so called image registration process is because the 2 imaging systems do not include necessarily lens having the same optical properties and because they may also not include the same resolution, and because they also are not necessarily well aligned.
US20110074989 provides a way to combine R, G or B pixels with depth-measuring pixels without taking into account the need for optimization of the depth-measuring active region, nor optimization of spatial aliasing that may occurs from the depthsensing pixels spatial arrangement. Additionally, the RGBZ image is created by interpolating the Z pixels on the RGB pixels which is prone to registration errors.